The research program is concerned with the development and parametric analysis of discrete trial, repeated measured procedures for the study of delayed matching and delayed response performance in animals, and with the utilization of these procedures for the isolation and measurement of drug effects on memory processes. The behavioral consequences of central cholinergic action are of particular interest. Results will be relevant to the following theoretical or conceptual issues: separation of drug effects on "registration," "storage," and on input into and retrieval from storage; relations between sensitivity to stimuli, delay duration, memory, and drug-induced "disinhibition"; and role of proactive interference in the deterioration of memory over time.